New engine for 28ft yacht - power or size/weight?

Captain Crisp

Captain Crisp

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Hi - I'm looking at a new engine for my 28ft Twister. My 10hp Volvo MD is coming to the end of its life...
At first I was thinking of going up to 15hp, but, wondering whether that's foolish, given extra weight/size etc...
After all, it is supposed to be a sailing boat...
Just wondered if there was any consensus/strong opinions on what's the best amount of power per size of yacht...?
Thanks,
Crisp
 
I had an 18hp VP in my Dufour 29, just about perfect. Gave hull speed cruising at around 2000rpm when the wind died, economical with some extra ‘grunt’ for pushing a tide. I’d certainly go for the bigger engine in your situation.
 
It may come down to what fits, but around 15hp should be OK and will give you a better cruising boat than 10hp. A friend of mine upgraded his Trapper 501 from 10 to 15 and it made a lot of difference. 15hp was fine with our old Sadler 29.

It may not be a good idea to over-engine. You may end up doing quite a bit of motor-sailing and the engine won't get the chance to work hard enough.
 
FYI, the Beta 10 and 14 have a very similar weight. You might not have to compromise on weight if you go that way. I took the 14hp for my 31ft S/V and am very happy. Only use it to get in and out of harbours anyway. If you are used to 10hp now anything similar will do just fine. At least that was my reasoning when buying. I'd go with something slightly stronger and that's it.
 
I had a Beta 10 HP in my Invicta 26 (similar hull design but much lower displacement 5000 lbs, compared to 9,900lbs), the 10 HP pushed her along happily at theoretical hull speed yet was still economical. I would suggest the Beta 25 HP would suit your boat well, the lower HP Beta 14 might be OK in most circumstances but it would have to work hard in others.
The physical size of the replacement engine is of course something to be considered, but Beta engines are quite compact.
 
Are you going to be fitting it yourself?
You'd quite possibly be able to do it if you went for a 'like for like' swap, which could save loads of dosh perhaps?
Actually, are you disappointed with the power output of your current engine?
Going even madder, you say it's coming to the end of its life; how about refurbing it with new rings, head gasket along with a company 'service' the head and injector?
Edit: A glass later, that'd give you an opportunity to paint the barrel and head, to polish the pipes and give it an aesthetic boost??
 
Chap on the Twister website put in 20hp so it can be done.

Problem with large props running in small apertures is that it is so noisy, it is difficult to imagine when you would need, or care, to use the extra power. I would be tempted to keep it smaller. The Beta 14 (13.5) looks a good compromise.

.
 
Used to be 3.5 HP/t, now 4hp/t more common for an auxiliary. Modern engines are much lighter and more compact these days. Our entire new engine installation ended up 20% lighter than the previous model, even with the heavy old transmission, and we ended up moving a fair bit of clutter to maintain our trim.
 
Many thanks all!
Really appreciate all this advice.
I'm veering towards Beta 14... but all options (including refurb...) still on the chart table...
Cheers,
Crisp
 
doug748 said:
Chap on the Twister website put in 20hp so it can be done.

Problem with large props running in small apertures is that it is so noisy, it is difficult to imagine when you would need, or care, to use the extra power. I would be tempted to keep it smaller. The Beta 14 (13.5) looks a good compromise
.
Click to expand...

I went into this with a similar boat and an aperture.

Because of the deadwood, when a blade faces north or south going forwards you lose power because there is nothing for it to grip. It may well be that a bigger engine might not be able to supply the anticipated benefit.
Also, most of the power from a propeller is it's diameter rather than pitch where you are limited .

In the end I went for a two bladed turbine prop and kept the same engine. At lest the prop was behind the deadwood for sailing with minimal drag.

The Twister is a lovely boat under sail and I suppose it depends how long you intend to keep it and how
much motoring you plan to do.
 
miha90 said:
FYI, the Beta 10 and 14 have a very similar weight.
Click to expand...

They are the same engine! The 10hp is the 14hp (actually 13.5hp) restricted to (IIRC) 3,000rpm instead of the 14hp's 3,600rpm.

You may get a larger output alternator as standard with the 14hp.

I had a Beta 14 in a heavy-ish long-keel 23 footer, and that was ample. I'd be tempted to look at the Beta 16hp (also a twin) and only 5kg heavier, or even the 20hp, a 3 cylinder, for the Twister and its 60% greater displacement.
 
Hey, just had a Beta 16 arrive today, to swap out a 2GM20 in a Jeaneau 29.2. Only prob is the delivery truck wiped out some over head cables to my neighbours..Not in residence.
The Beta is fresh cooled and looks to be a good replacement. Now need to find a home for the Yanmar. Runs OK, just a bit oily in the exhaust.
DW
 
I just re-engined my Twister with a 1GM10 which was a like-for-like swap for the older 1GM. It meant that I could do the job easily myself as everything was exactly the same. The 1GM 10 is sufficient to push the boat to hull speed in flat water but little in reserve for head seas. If I was re-engineing from scratch I’d go for a Beta 14 Or 16. However, it would cost me about four times as much
 
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